Messages in this thread Patch in this message | | | Subject | Re: [PATCH 2/4] fs: Remove FIRMWARE_PREALLOC_BUFFER from kernel_read_file() enums | From | Scott Branden <> | Date | Fri, 10 Jul 2020 15:10:25 -0700 |
| |
On 2020-07-10 3:04 p.m., Matthew Wilcox wrote: > On Fri, Jul 10, 2020 at 02:00:32PM -0700, Scott Branden wrote: >>> @@ -950,8 +951,8 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, >>> goto out; >>> } >>> - if (id != READING_FIRMWARE_PREALLOC_BUFFER) >>> - *buf = vmalloc(i_size); >>> + if (!*buf) >> The assumption that *buf is always NULL when id != >> READING_FIRMWARE_PREALLOC_BUFFER doesn't appear to be correct. >> I get unhandled page faults due to this change on boot. > Did it give you a stack backtrace? Yes, but there's no requirement that *buf need to be NULL when calling this function. To fix my particular crash I added the following locally:
--- a/kernel/module.c +++ b/kernel/module.c @@ -3989,7 +3989,7 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) { struct load_info info = { }; loff_t size; - void *hdr; + void *hdr = NULL; int err;
err = may_init_module();
| |